1. Field of the Invention
This invention relates to a porous article of a nickel-titanium alloy having medical and non-medical applications.
2. Description of Prior Art
Nickel-titanium alloys are known shape memory alloys which have been proposed for use in various environments including robotics and in memory devices of medical implants.
Soviet Union Patent Specification 1,381,764 dated 1982 proposes implants for facial reconstruction fabricated from a nickel-titanium alloy having a porosity of 8-60%, but the disclosure is very limited and there has been no commercial development of the material described.
U.S. Pat. Nos. 4,206,516; 4,101,984; 4,017,911 and 3,855,638 all describe composite implants having a solid substrate with a thin porous surface coating. U.S. Pat. No. 3,852,045 describes a bone implant element of porous structure in which the pores are developed by means of solid expendable void former elements which are arranged in a selected spatial pattern in a form cavity; metallic particles are packed about the void former elements, the mix is densified, the void former elements are removed, such as by vaporization and the metallic particles are sintered.
The search continues for materials suitable for fabricating medical implants, and for materials of improved physical characteristics.